Geography

Border region

Following the 1970 Boundary Treaty between the United States and Mexico that settled all then pending boundary disputes and uncertainties related to the Rio Grande (Río Bravo del Norte) border, the international continental border extends 3,145 kilometres (1,954 mi), excluding the maritime boundaries of 29 kilometres (18 mi) in the Pacific Ocean and 19 kilometres (12 mi) in the Gulf of Mexico.[1][2]

According to the International Boundary and Water Commission, this continental border follows the middle of the Rio Grande—according to the 1848 Treaty of Guadalupe Hidalgo between the two nations, "along the deepest channel" (also known as the thalweg)—from its mouth on the Gulf of Mexico a distance of 2,019 km (1,255 mi) to a point just upstream of El Paso and Ciudad Juárez.[3] It then follows an alignment westward overland and it is marked by monuments for a distance of 859 km (534 mi) to the Colorado River, when it reaches its highest elevation at the intersection with the Continental Divide. Thence it follows the middle of that river northward a distance of 38 km (24 mi), and then it again follows an alignment westward overland and marked by monuments a distance of 227 km (141 mi) to the Pacific Ocean. miles, excluding the maritime boundaries of 18 miles in the Pacific Ocean and 12 miles in the Gulf of Mexico.

The official 'border region' extends 60 kilometres (37 mi) north and south of the aforementioned boundaries and 60 kilometres (37 mi) east into the Gulf of Mexico and 60 kilometres (37 mi) west into the Pacific Ocean.

The region is characterized by deserts, rugged hills, abundant sunshine, and two major rivers—the Colorado and the Rio Grande (Río Bravo del Norte)—which provide life-giving waters to the largely arid but fertile lands along the rivers in both countries.

In the United States, Texas has the longest stretch of the border of any State, while California has the shortest. In Mexico, Chihuahua has the longest border, while Nuevo León has the shortest.

Texas borders four Mexican states—Tamaulipas, Nuevo León, Coahuila, and Chihuahua—the most of any U.S. state. New Mexico and Arizona each border two Mexican states (Chihuahua and Sonora; Sonora and Baja California, respectively). California borders only Baja California.

Three Mexican states border two U.S. states each Baja California borders California and Arizona; Sonora borders Arizona and New Mexico; and Chihuahua borders New Mexico and Texas. Tamaulipas, Nuevo León, and Coahuila each border only one U.S. state Texas.

Crossings

The border separating Mexico and the United States is the most frequently crossed international boundary in the world,[4][5][6] with approximately 350 million legal crossings being made annually.[5][7][8]

There are 45 U.S.–Mexico border crossings with 330 ports of entry.[9] From west to east, below is a list of the border city twinnings, which are municipalities connected by one or more legal border crossings.

History

In the mid-16th century, with the discovery of silver, settlers from a variety of countries and backgrounds began to arrive in the area. This period of sparse settlement included colonizers from different backgrounds. The area technically was part of the Kingdom of New Spain, but due to the lack of population and the diverse citizenry it had, it did not seem to belong to any country. This period lasted until the early 19th century at which point the United States bought the lands known as the Louisiana Purchase from France and began to expand steadily westward in its pursuit of Manifest Destiny.[10]

El Paso (top) and Ciudad Juárez (bottom) seen from earth orbit; the Rio Grande is the thin line separating the two cities through the middle of the photograph. El Paso and Juarez make up the second largest international metroplex after San Diego and Tijuana.

The border itself was not clearly defined and remained so until the Mexican colony became independent from Spain and entered a period of political instability. Mexico attempted to create a buffer zone at the border that would prevent possible invasion from the North. The Mexican government encouraged thousands of their own citizens to settle in the region that is now known as Texas and even offered inexpensive land to settlers from the United States in exchange for populating the area. The influx of people did not provide the defense that Mexico had hoped for and instead Texasdeclared its independence in 1836. That independence lasted until 1845 when the United States annexed Texas.

The constant conflicts in the Texas region in the mid 19th century eventually led to the Mexican-American War, which began in 1846 and ended in 1848 with the Treaty of Guadalupe Hidalgo. Due to the treaty, Mexico lost more than 960,000 square miles (2,500,000 km2) of land, 55%[11] of its national territory, including what is today California, Arizona, New Mexico, Utah, Nevada and parts of Colorado, Wyoming, Kansas, and Oklahoma. In addition, all disputes over Texas and the disputed territory between Rio Grande and Rio Nueces were abandoned. Five years later the Gadsden Purchase completed the creation of the current United States–Mexico border. The purchase was initially to accommodate a planned railway right-of-way. These purchases left approximately 300,000 people living in the once disputed lands, many of whom were Mexican nationals. Following the establishment of the current border a number of towns sprang up along this boundary and many of the Mexican citizens were given free land in the northern regions of Mexico in exchange for returning and repopulating the area.[12]

The Treaty of Guadalupe Hidalgo and the Treaty of 1884 were the agreements originally responsible for the settlement of the international border, both of which specified that the middle of Rio Grande was the border—irrespective of any alterations in the channels or banks. The Rio Grande shifted south between 1852 and 1868, with the most radical shift in the river occurring after a flood in 1864. By 1873 the river had moved approximately 600 acres (2.4 km2), cutting off land that was in effect made United States territory. By a treaty negotiated in 1963, Mexico regained most of this land in what became known as the Chamizal dispute and transferred 264 acres (1.07 km2) in return to the United States. Border treaties are jointly administered by the International Boundary and Water Commission (IBWC), which was established in 1889 to maintain the border, allocate river waters between the two nations, and provide for flood control and water sanitation. Once viewed as a model of international cooperation, in recent decades the IBWC has been heavily criticized as an institutional anachronism, by-passed by modern social, environmental and political issues.[2]

The economic development of the border region on the Mexican side of the border depended largely on its proximity to the United States, due to its remoteness from commercial centers in Mexico. During the years of Mexican President Porfirio Díaz, between 1876 and 1910, the border communities boomed, due mostly to close ties to the United States, and the Mexican government's support for financial investments from the United States.[13] Railroads were built that connected the northern Mexican states more to the United States than to Mexico and the population grew tremendously. The mining industry also developed, as did the United States’ control of it. By the early 20th century companies from the United States controlled 81% of the mining industry and had invested five hundred million dollars in the Mexican economy overall, twenty-five percent of it in the border regions.[14]

100-km border region

The Mexican Revolution, caused at least partially by animosity towards foreign ownership of Mexican properties, began in 1910. The Revolution increased the political instability in Mexico, but did not significantly slow United States investment. It did reduce economic development within Mexico, however, and the border regions reflected this . As the infrastructure of communities on the United States side continued to improve, the Mexican side began to fall behind in the construction and maintenance of important transportation networks and systems necessary to municipal development.[14]

Security

U.S.–Mexico border enforcement

The U.S.–Mexico border has the highest number of legal crossings of any land border in the world.[4] Over five million cars and trucks travel through the border annually.[15] According to Vulliamy, one in five Mexican nationals will visit or work in the United States at one point in their lifetime.[15] As of 2010, the border is guarded by more than twenty thousand Border Patrol agents, more than at any time in its history.[16] However, they only have "effective control" of less than 700 miles (1,100 km) of the 1,954 miles (3,145 km) of total border,[17] with an ability to actually prevent or stop illegal entries along 129 miles (208 km) of that border.[18] The border is paralleled by United States Border Patrol Interior Checkpoints on major roads generally between 25 and 75 miles (121 km) from the U.S. side of the border, and garitas generally within 50 km of the border on the Mexican side.[19][20][21]

In January 2013, the Government Accountability Office released a report stating that the United States Border Patrol only intercepts sixty-one percent of individuals illegally crossing the border in 2011, which translated to 208,813 individuals not being apprehended.[23] 85,827 of the 208,813 would go on to illegally enter the United States, while the rest returned into Mexico.[23] The report also showed that the number of illegal border crossings has dropped.[23]

Border incursions

Border for pedestrians in Tijuana, Baja California

According to the United States Border Patrol, in the fiscal year of 2006, there were twenty-nine confirmed border incursions by Mexican government officials, of which seventeen were by armed individuals. Since 1996 there have been 253 incursions by Mexican government officials.[24][25][26] In 2014, United States Department of Homeland Security informed United States Representative Duncan D. Hunter, that since 2004, there have been 300 documented border incursions, which resulted in 131 individuals being detained.[27]

The Washington Times has reported that on Sunday, August 3, 2008, Mexican military personnel who crossed into Arizona from Mexico encountered a U.S. Border Patrol agent, whom they held at gunpoint. The soldiers later returned to Mexico, as backup Border Patrol agents came to investigate.[28][29]

Disagreements over need for more resources

Proponents of greater spending on the border – especially politicians from border states – argue that continuing the buildup is necessary due to increased violence and drug trafficking from Mexico spilling over into the United States.[30] However, critics such as the Washington Office on Latin America (WOLA) have argued that further buildup will have fewer desired effects and may even be counterproductive. Furthermore, WOLA has emphasized that the diminishing number of border crossings can only be partially attributed to US security measures. Unintentional factor such as weakening US economy in the wake of the 2008 financial crisis and increased violence in the north of Mexico has made attempting illegal border crossings more risky and less rewarding.[31]

Environment

History

The Agreement on Cooperation for the Protection and Improvement of the Environment in the Border Area, known as the La Paz Agreement, was signed into law on August 14, 1983 and became enforceable on February 16, 1984.[32] This agreement to protect the environment is the political foundation between the U.S. and Mexico for 4 subsequent programs. Each program has addressed environmental destruction in the border region resulting from the rise of the maquiladora industries, those who migrated to Northern Mexico to work in the industries, the lack of infrastructure to accommodate the people, Mexico's lax regulations concerning all these factors, the resulting spillover into the U.S., and the U.S.'s own environmentally destructive tendencies. The programs were: IBEP (1992), Border XXI (1996), Border 2012 (2003) and Border 2020 (2012).[33]

Travel

Western Hemisphere Travel Initiative

In late 2006, the United States Department of Homeland Security (DHS) announced a rule regarding new identification requirements for U.S. citizens and international travelers entering the United States implemented on January 23, 2007; this final rule and first phase of the WHTI specifies nine forms of identification—one of which is required to enter the United States by air: a valid passport; a passport card; a state enhanced driver's license or state enhanced non-driver ID card (available in Michigan, New York, Vermont, and Washington[34]) approved by the Secretary of Homeland Security; a trusted traveler program card (NEXUS, FAST, or SENTRI); an enhanced tribal identification card; a Native American Tribal Photo Identification Card; Form I-872 – American Indian Card; a valid Merchant Mariner Document when traveling in conjunction with official maritime business; or a valid U.S. military identification card when traveling on official orders.[35][36][37][38]

Busiest border

The Mexico–United States border is the world's busiest border, specifically the crossing at San Diego, California to Tijuana, Mexico, known as the San Ysidro Port of Entry.[39] In the U.S., Interstate 5 crosses directly to Tijuana, and the highway's southern terminus is this crossing. In 2005, more than 17 million vehicles and 50 million people entered the U.S. through San Ysidro.[40][41][42][43] Among those who enter the United States through San Ysidro are "transfronterizos", American citizens who live in Mexico and attend school in the United States.[44]

Along the Mexican coast of Baja California, there are neighborhoods of Americans living in Tijuana, Rosarito Beach, and Ensenada, whose residents commute to the United States daily to work.[45] Additionally, many Mexicans also enter the United States to commute daily to work.[46] In 1999, 7.6% of the labor force of Tijuana was employed in San Diego.[47]

Mexico-United States barrier

The U.S. government had plans in 2006, during the Bush administration, to erect a border fence along the U.S.–Mexico border. The controversial proposal included creating many individual fences. Almost 600 miles of fence was constructed, with each of the individual fences composed of steel and concrete.[15] In between these fences are infrared cameras and sensors, National Guard soldiers, and SWAT teams on alert, giving the name a "virtual fence".[15] Construction on the fence began in 2006, with each mile costing the U.S. government about $2.8 million.[9] In 2010, the initiative was terminated due to costs, after having completed 640 miles (1,030 km) of either barrier fence or vehicle barriers, that were either new or had been rebuilt over older, inferior fencing. The Boeing-built SBI-net systems of using radar, watchtowers, and sensors (without a fence or physical barrier) were scrapped for being over budget, full of glitches, and far behind schedule.[48]

Portion of border near Jacumba, California in 2009 with enhanced security

Animals

When animals are imported from one country to another, there is the possibility that diseases and parasites can move with them. Thus, most countries impose animal health regulations on the import of animals. Most animals imported to the United States must be accompanied by import permits obtained in advance from the U.S. Department of Agriculture's Animal and Plant Health Inspection Service (APHIS) and/or health certification papers from the country of origin.

Veterinary inspections are often required, and are available only at designated ports;[49] advance contact with port veterinarians is recommended.[50] Animals crossing the United States-Mexico border may have a country of origin other than the country where they present for inspection. Such animals include those from the U.S. that cross to Mexico and return, and animals from other countries that travel overland through Mexico or the U.S. before crossing the border.

Per APHIS, horses originating from Canada can enter the United States with a Canadian government veterinary health certificate and a negative test for EIA.[51] Horses from Mexico must have a health certificate; pass negative tests for EIA, dourine, glanders, and EP at a USDA import center; and undergo precautionary treatments for external parasites at the port of entry. Horses from other Western Hemisphere countries must have the same tests as those from Mexico and, except for horses from Argentina, must be held in quarantine for at least seven days as a check for VEE.

APHIS imposes similar testing and certification requirements on horses from other parts of the world but without the quarantine for VEE. These horses are held in quarantine—usually three days—or until tests are completed. Because the disease equine piroplasmosis (equine babesiosis) is endemic in Mexico but not established in the United States,[53] transportation of horses from Mexico to the United States requires evaluation of horses for the presence of this disease.

Transportation of horses from Mexico to the United States normally requires at least three days in quarantine, which is incompatible with most recreational equestrian travel across the border. A leading exception to this rule is the special waiver obtained by riders participating in the Cabalgata Binacional Villista (see cavalcade).

Crossing from the United States to Mexico

Import from the United States to Mexico requires evidence within the prior 45 days of freedom from equine infectious anemia, among other requirements.[54]